They are everywhere!
Imagine having an ancestor who is 3.8 billion years old and who would dive into a pool filled with boiling water. Well, that is everyday life for some microorganisms. Not only are they the oldest form of life on the planet, but they can also live in almost every environment, even the most extreme ones.
A bacterium that likes the cold: Polaromonas vacuolata
The Arctic and Antarctic oceans are the refuge of microorganisms that like the cold, the psychrophiles. Eucaryotic cells, algae, diatoms, and bacteria colonize these frozen seas. P. vacuolata, for example, is a bacterium whose growth is optimal at 4°C and whose reproduction is inhibited at 12°C, a temperature that it finds already too high. These cold-loving bacteria are important for producers of processed foods, fragrances, and laundry detergents since their enzymes work at freezing temperatures.
An extremophilic bacterium: Thermus aquaticus
In the 1960s, a team from the University of Wisconsin in Madison discovered T. aquaticus, the first extremophilic bacterium to be identified. This bacterium likes extreme conditions, since it lives in thermal waters where the temperature is greater than 70°C. This microorganism’s thermostable enzymes have made possible the technology called “polymerase chain reaction” used in research laboratories since the 1980s.
Bioluminescent algae: Pyrocystis lunula
Pyrocystis lunula can be seen in the Atlantic ocean on the coast of São Paulo and in the Pacific ocean close to the shore of California. These algae with two flagella are unicellular, microscopic, and... bioluminescent. Like fireflies, they produce their own light.